A process for the production and purification of non-infectious Human Immunodeficiency Virus-like particles form mammalian cells infected with recombinant vaccinia viruses may be developed. A procedure to produce milligram quantities of HIV-like particles will be designed using vaccinia recombinants that simultaneously express the env, gag, and pol genes of HIV. A systematic evaluation of several mammalian cell lines and various culture conditions will be undertaken to maximize the yield of virus-like particles. In addition, processes will be developed for the characterization and purification of these particles consistent with their use as vaccine immunogens in animal trials. The ability to produce commercial quantities of non-infectious HIV particles, by these processes, will provide a completely safe alternative to the use of whole inactivated HIV as a vaccine for AIDS.